Electric-arc lamp



July 13 1926.

' H.T.HARRBON ELECTRIC ARG LAMP l l l l QN n m w m Filed Feb. 4, 1919July 13, 1926.

H. T. HARRISON ELECTRIC ARC LAMP Filed Feb. y 4, 1919 3 Sheets-Sheet 2myw- July 13,1926. l 1,591,914

AH. T. HARRISON ELECTRI C ARC LAMP 3 Sheets-Sheet ',3

Filed Feb. 4, 1919 5y Mmm/19)# A ATTORNEYS.

Patented July 13, 1926.

HAYDN TETES HARRISON, OF WESTMINSTER. ENGLANB.

ELECTRIGARC LAMP.

Application filed February a', 191.9, Serial Ne 274,892; and in GreatBritain Gctober 14, 1915.

(GRANTED UNDER THE IRQVISIQNS Gl? THE ACT 0F MARGH 3, 11521, 11 STAT.L., 1313.)

Applications for patents have'been filed in Great Britain on October141, 1915, and Janquired rate, to improved means for causing thestriking of the are to be effected automatically on the lamp circuitbeing closed, and to the general constriuztion arrangement, andoperation ofV the parts of the lamp.

In order that the invention may be readily understood reference will bemade to the accompanying illustrative drawings in Which-- Fig. 1 is anelevation showing the general arrangement of a lamp constructedaccordnp; to the invention. y

Fig. 2 is a longitudinal section on the line .fc of lfiga 1` Fig. 3 isAa cross of Fig. 1.

Fios. el and 5 show respectively in longitudinal section and in Crosssection and to a larger scaleY than Fig. 1, a modified arrangement forfeeding the carbons at the desired rate.

Fig. 6 shows partly in end elevation and partly in cross section andFig. 7 in side elevation other arrangements for feeding the carbons.

Fig. 8 is a diagrammatic perspective view showing the are strikingmechanism used in the lamp.

Referring toFigs. 1, 2 and 3, Al and B are respectively the positive andnegative carbons mounted in heads 1, 1a, (hereinafter called carbonheads) which are supported in stationary parts C of the lamp and are re`spectively rotatedI by worm. gearing 2, 2a and 3, 3a operated from adriving wheel 4 rotated by an electric motor 5. The driving wheel 4 issecured on a vertical shaft 6 carrying the worm 2 of the Worm gearing2*-2 and is provided at a suitable position section on the line y y and3, each tubehas tix with a bevel wheel 7 engaging a bevel wheel 8 [inedto one end of a horizontal shaft 9 that is provided at its other endwith a bevel. wheel 19. This wheel engages bevel wheel 11 fined on arotatable shaft lil connected by a. flexible coupling 13 to a shaft 111on to which is fixed the worin 3a of the worm gearing -Ba.

The carbone A and B are each mounted in metal tube or cartridge 15 fromonel end of which the forward end of the carbon projects.

To ensure good electric contact with the source of electric supplythrough the metal tube or cartridge 15', the carbon is forced between.metal Contact jaws 16. These jaws are formed as a cone clutch (Fig. l).which' is forced at one end against a cone shaped seat 16a in the carbonhead by the cone shaped forward end or head 15PN of the correspondingtube or cartridge 15 and thereby caused to closel around and upon thecarbon. Each tube ror cartridge 15 (hereinafter called a tube) is heldin" position inthe corresponding carbon head in such way that it can bereadily disconnected therefrom when it is desired to insert a new carbonand to be afterwards readily replaced and held in position endways, theprojecting end of the new carbon being passed through the carbon head soas to eject the remaining portion of the previous carbon. In thearrangement shown for -this purpose, in the Figs. 1, to it a collar 15"that tits the rear end ofthe carbon head 1 or 1a and is provided with acircular vflange or head 15c againstwhich normally bears in an endwaysdirection the forked end 17a of a lever 17. rll"his lever is pivoted at17 to a fixed part of the lamp and is held in the operative position bya spring controlled handle 18 that is jointed at 17d to an arm 17C on alever 17 and is connected by' a pin 1S"jl to one end of a coiled spring19 the other end of which is connected to a 'xed pin 19a. Thearrangement is such that the lever 17 will be held with an elasticpressure in its operative position when the pin 18 bears against itabove the pivot 17b and it will be moved away from'the collar or head15" and held in a lowered and inoperative position7 to remove endwayspressure on the tube 15 and allow the tube to be removed when the handle18 and spring 19 are moved downward so as to cause the pin 18a to bearagainst a curved seat 18d on the lever.

Means are provided whereby the tube 15 can be prevented from rotatingwith the corresponding carbon head when t-he carbon is to vbe fedforward, and released, so as to allow it to rotate with the carbon head,when feeding` of the carbon is not required. For this purpose, in theexample shown in Figs. 1. 2 and 3, the flange or head l5C is formed withteeth 15"1 with which can be engaged a spring controlled detent- 15ethat is pivoted at 15f and can be disengaged from the flange or head bya hand operated lever 15"; when it is desired to release the tube 15 andallow it to be rotated by the carbon head 1 or 1, as the case may be.

Each tuoe 15 is screw threaded internally to engage with a screwthreaded carriage or traveller 2O (hereinafter called a traveller),adapted to force the corresponding carbon A forward when the tube 15 isheld stationary, the traveller being then rotated relatively to the tubeby the carbon which receives its rotary motion from the rotating headthrough the cone clutch 16. For this purpose, the rear end of the carbonis shaped to tit into a correspondingly shaped hole in the traveller 20,after the manner el a plug and socket oint, so lthat the carbon andtraveller can rotate together. When the tube 15 is held stationary theclutch members 15a and 16 slip. It will readily be seen that when thetravellers 2O in the two tubes 15 are rotated and the tub-es 15 are heldstationary` the carbons will be ted forward but when the tubes areallowed to rotate with the carbon heads, 1, 1a, there will be no feedingforward of the carbons.

In the simplest 'form of the lamp, when it is not desired to regulateth-e rate of burning of the carbons beyond such regulation as isobtained by suitably winding the electric motor 5, each tube 15 isprovided internally with a line screw thread 15h (Figs. 1, 2, and 3) otexactly the pitch necessary to produce the required rate of feed of thecarbon.

Or, if the required screw thread 15h would be too line to beconveniently cut. the traveller 2O can be connected to the rotatingcarbon through a suitable speed reducing gear whereby the speed ofrotation of the traveller can be reduced relatively to the speed ofrotation of the carbon. A con venient form of reducing gear ot this kindis shown in Figures 4 and 5 wherein there is keyed or otherwiseconnected to one end of the carbon, marked B, a circular block 21 towhich is secured a spindle 22, carrying a pinion Q3. A sleeve 24 ismounted on the block 21 and is provided with a feather 25 engaging in aslot 26 in the tube 15. The sleeve Qfl is provided with an internallytoothed wheel 27. The traveller 20, which is screw threaded externallyand engages the screw thread 15?* ol the tube 15. is provided with aspindle 28 on which is mounted a loose pinion 29 that gears with thepinion 23 and with the wheel 27. rlhe parts are held together by a head2Q on the spindle QQ screwed into the block 21. The rotation ot thecarbon B rotates the circular block S21 and the pinion 23, which rotatesthe pinion 29. and as the wheel 2T is fixed, the pinn ion Q9 and itsspindle 28 are carried round the wheel 27, thereby effecting therotation of the traveller 2() at a slower rate than that ot' the carbon.As the traveller' engaged with the said thread 15u et the tube 15, thetraveller and consequentliY the carbon and associated parts are tedforward. By suitably choosi the number ot teeth on the rcspective wheels23 27 and 297 any desired reduction in the speed of' rotation oit thetraveller 2O relatively to that oi" the carbon B can be obtained.

lli/diere, owing to variation in the rate of consumption of differentbatches oi.z carbous, or for any other reason?, it may be desir-ed tovary the rate ot `leed oit' the carbon,y when the lamp is burn ing., the'form of reed mecha nism shown in Figure 6 may be employed. ln this thetube 'l5 is so anse-l as normally to rotate with the carbon head l or1fL and carbon A or B, so that no feeding of the carbon then tairesplace. and means are provid-ed whereby rotation of the lube can bearrested when desired to enable the traveller therein to be fed torwardby screwing itself endways in the tube Various means may be provided torarresting the rotary motion oi the tube under the action olE a movingpart ci the lamp tor the purpose set forth. In the example shown 'for'this purpose in Fig. 6. a ratchet wheel 8O is used that is fixed on thetube 'l5 and cooperates with a stop device` shown pawl 31 carried on apivoted bell cr: fil'. .ever 333. one arm namely oi" which is loaded asbj.' making it heavier than the arm or by providing it with acouuterweight 3:3 or equivalent the other arm l2 being provided with aroller 3st or the like that bears (miur-t a cam or eccentric oreouiralcnt lever operating device. The cam is rotated e'itb'r' directlyor indirectly by a suitable rola member ot' the lanip.v for instance thecoi spending rotating carbon bolder l or lj. lhen the pawl under thecontrol ot the cam or equiif'alent device and the action of the weightedarm 33 et the lever is caused to engage the ratchet wheel 9,0. t(rotation oi this wheel and tube 15 is stopped. and the carbon is thented forward by th. rotation ot the traveller 2O in the tube during eachperiod ot rest or' the tube. The duration of each period of rest ot thetube 15 can be adjusted externally to the tub-fi by altering therelative positions ol the pawl 31 lUU horizontal shaft 9.

und the roller 34, or other equivalent means may be employed. e f

The pawl clutch member 3233, or equivalent may be attached to a rod thatcan'be depressed or raised by hand to throw the ar-l resting device outof or into operation when desired and thus allow of the carbon feedbeing effected by hand.

Fig. 7 shows another feeding varrangement wherein the tube l5 used in'the other arrangement, is dispensed with and the rotary carbon A ismoved endways by a Vtraveller 2O that is engaged by a screw threaded rod36, which runs parallelk to the carbon marked A, and is rotated by anyconvenient means from 'a moving part of the lamp but is prevented frommoving endways. ln the example shown, the second rod 36 is rotated in anintermittent manner, by one or more pins 87, one being shown, carried bythe worm wheel 2 of the worm gearing 2, 2av used for rotating thecorresponding carbon head l, the pin 37 being arranged to engage a starwheel 38 fixed on the screw threaded rod 36. It will thus be seen thateach time the screw threaded rod is partly rotated, the travellerQO willbe moved forward carrying the carbon A with it. The screw threaded rod36 is supported at its end by fixed parts 36a, 36h of the lamp and itmay be provided with a hand wheel by which it can be rotated by hand,when desired.

In order to cause the striking of the arc to be eiiected in an automaticmanner on closing the switch controlling the lamp circuit, and also atother times during the working of the lamp, there is employed a movablecontactpiece 39, (Figs. l and 8) consisting for example of a finger ofcarbon, `metal or other suitable conducting material. rlhi's contactpiece is secured to an arm 39a ii'xed on a spindle l() which is mountedin bearings 40a and oscillated about a horizontal aXis by a rod 4lconnected to a crank pin 40h on the spindle 40. The rod 4l is providedwith an extensionv lll@L by means of which `it can be raised by a rotarycam 42 fixed on the The rod, at' its lower end, is connected to thearmature i3 of an electro-magnet 44, or solenoid, in series with thelamp circuit. On the lamp circuit being closed and the carbon heads l,lEL set in rotation by the motor 5 through the shafts `6 and 9, the cam4t2 will, during` its rotation, permit the collar lla and rod 4l to falland turn the spindle Ll0 and arm 39a in a direction toV cause thecontact piece 39 to touch the opposing tips of the carbone A, B, it itis not already doing so, and on the cam afterwards acting to raise theextension lll and rod 4l, the contact piece 39 will be withdrawn to forman electric arc between the carbons. The contact piece is then furtherwithdrawn from the region of the arc by the operation of the armature 43of the electro- 'rotating said carbon holder therefrom,

magnet 4A or equivalent, which is now eX- cited owing to the lampcircuit being completed through the arc and the winding of theelect1o-magnet,the armature retaining the contact piece in the retractedsafe position as lon@ as the current is flowing (see Fig. 8). The cam 42can then: no longer. act upon the rod Al, owing to the upward movementof the rod 4l having removedV its operative part lla out of engagementwith the cam 42. On the current ceasing to flow across the carbons, thearmature i3 will fall away from the electro-magnet' 44, under the actionof gravity, or its equivalent, and thereby, through the downwardmovementof the rod il with extension 4l, enable. the cam l2 to again come intooperation to. again cause the contact piece 39 to move into and out ofContact with the carbon tips and so again cause the arc to be struck ifthe circuit switch be still closed.

It desired, more than vone movable contact piece mounted and operated ashereinbefore described with reference to the 'contact piece 39 may beused to prevent any possiblefailure to strike the arc when required.

rl`he carbonheads` l, 1a are preferably arranged atV an angle to oneanother as shown.

That I claim is l. An electric arc, lamp of the class describedcomprising opposite rotary carbon holders, means for preventingendwise move-- ment thereof, a motor having connections for rotatingsaid carbon holders in unison', rotary feeding mechanism associated witheach holder and actuated therefrom to feed a carbon therethrough, andmeans for disconnecting either feeding mechanism.

2. In an electric arc lamp of the c? ass described, a rotary carbonholder, means tor preventing endways movement thereof, a motor connectedto rotate said holder, means for automatically feed-ing a carbon endwisethrough the holder while being rotated thereby, a toothed member uponsaid holder, and a cooperating engaging member to retain the holderagainst rotation to effect a feed of the carbon.

3. In an electric arc lamp of the class described, a rotary carbonholder provided with a friction clutch adapted to engage and rotate acarbon while permittingA an endwise feed therethrough, a motor, meansfor an internally screw threaded tube normali, held in frictionaldriving connection with said rotary holder, means for retaining saidtube against movement when desired, a traveller for moving the carbonendwise, and feeding means for said traveller engaging the thread of thetubeand thereby actuated from the rotary holder.

1l. In an electric arc lamp of the class de scribed, a rotary carbonholder constructed to clamp and rotate carbon while permitting endwisefeed therethrough, a. tube disposed co-axial with said carbon and holderand frictionally engaged with the latter, a traveller located within thetube and actuated b y the rotary motion thereof, and a control leverarranged to retain the tube in such frictional engagement.

5. In an electric arc lamp of the type herein referred to, a rotar?,Tcarbon holder adapted to clamp and rot-ate a carbon ei;- tendingtherethrough but so as to admit of the carbon being moved endways, aninternally screw threaded tube arranged coaxial with said carbon holderand associated carbon, and in releasable engagement with said carbonholder so as to rotate therewith, means whereby said tube can be heldstationary, a traveller located within the tube and in operativeengagement with the screw threaded portion of said tube, a rotary bodyadapted to exert endways pressure on the rear end of the carbon andspeed reducing mechanism disposed within the tube and comprising anannular gear and pinioiis bctween said rotary body and traveller.

6. In an electric arc lamp of the kind in which each carbon is rotatedabout its longitudinal axis by an electric motor, a movable contactdevice under the control of the motor whereby it is adaptedautomatically to move into a position to bridge the tips of the carbonsand afterwards to be moved away therefrom by the motor to strike an arcbetween them and means for holding` the contact piece out of the controlof the motor when an arc is formed between the carbons.

7. In an lelectric arc lamp of the hind in which each carbon of a pairthereof is rotated about its longitudinal axis, a movable conductingcontact device adapted to bridge the tips of the carbone, means adapted,when the lamp is in action, to cause the contact device to move againstand from the carbons to strike an arc between. them and electromagneticmeans the circuit of which is arranged to be closed through the arc andadapted, when an arc is formed between the carbone. to hold the contactdevice in an inoperative position.

8. In an electric arc lamp of the kind in which each carbon of a pairthereof is rotated about its longitudinal axis, a movable conduct-ingcontact device adapted to bridge the tips of the carbone, oscillatingmeans adapted to move the contact device towards and from the carbone tostrike an are between them, a cam device operated from a moving` part ofthe lamp. and adapted to bring about the oscillation of the oecillatmeans, and electro-magnetic means the circuit of which is arranged to beclosed through the are and adapted, when an arc is formed between thecarbone, to hold the con 05 tact device in an inoperative position.

9. In an electric arc lamp of the hind in which each carbon p thereofrotated about its longitudinal able conducting contactdcvice adapted to.'0 bridge the tips of the carbone, a carrying said contact device, arotary bc carrying said arm, a rod connected to sait. body and adaptedto oscillate the same and attached arm and contact device, said rodlieing adapted to move cndwise automatically, in one dir Action. a canioperated fr a movin;r part of said lamp and adapted to move said rod inthe opposite direction and electro-magnetic means the circuit of whichis arranged to be closed through the arc and adapted, when an arc isformed between the carbons, to hold the Contact device in an inoperativeposition.

lO. In an electric arc lamp of the hind in which each carbon of a pairthereof rotated about its longitudinal axis. a morable conductingcontact device adapted to bridge the tips of the carbone, a lever armcarrying said contact device, a horizontal spindle mounted to turn abouta horizontal axis and to which said arm is izted, a vertical rodconnected to said spindle and adapt ed to oscillate it and the attachedarm and Contact device, said rod normally having a 05 tendency to falland move said contact de- Vice against the tips of the carbons, a rotarycam adapted to be continuously operated from a moving part of the lampwhen the lamp is in action and to move the rod in a direction towithdraw the Contact dcvice from the carbons and an electro-magnethaving its winding arranged to he in the circuit of the arc when struckand having au armature adapted when attracted to raise l0-r the said rodand hold the contact device in its inoperative position.

Signed at London, England, this elerenth day of December, 1918.

HAYDN 'lll-HES HARRISO-t.

